- Cataract is a clouding, or opacity of the lens that leads to blurring of vision and eventual loss of sight. The opacity of the lens is caused by chemical changes in the protein of the lens because of slow degenarative changes of age, injury, poison or intraocular infection.
- Cataracts occur so often in the aged. At 80 years of age, about 85% of all people have some clouding of the lens.
- Risk factors for cataract development includes diabetes, exposure to ultraviolet light or high dose radiation, and drugs such as corticosteroids, phenothiazines, and some chemotherapy agents. If untreated, cataracts progress to blindness.
Classification of Cataract
- Senile cataracts commonly develop in elderly patient because of degenerative changes in lens proteins.
- Congenital cataracts occur in neonates as genetic defects or possibly from measles in the mother.
- Traumatic cataracts may occur after injury sufficient to force vitreous humor into the lens capsule.
- Secondary cataracts may occur following other eye or systemic diseases.
- Gradual painless vision loss, blurred or distorted vision.
- Pupil may appear milky or white.
- Slit-lamp examination provides magnification and confirms diagnosis of an opacity.
- Other testing to rule out coexisting condition of the eye; tonometry (to determine if there is increased intraocular pressure [IOP], direct and indirect opthalmoscopy ( to rule out disease of retina), perimetry (to detect any loss of visual field).
- Surgery is the only cure and is recommended when vision causes problems in daily activities. Extracapsular extraction is usually done by cryosurgery or phacoemulsification under local anesthesia.
- Eye drops are given to decrease response to pain and lessen motor activity of the eye.
- Medication is given to reduce IOP.
- An intraocular lens implant is usually inserted at the time of surgery, designed for distance vision.
- Congenital cataract is corrected within first 3 months followed by cataract lens to correct vision.
- Nonsteroidal anti-inflammatory agents, antibiotic ointments, and possible corticosteroids may be necessary after lens implantation to reduce inflammation on other eye structures and prevent infection.
- If patient is not candidate for lens implant, the lens and capsule are removed (intracapsular extraction), and eye glasses and contact lenses are used to correct vision.
- Before surgery, monitor for worsening of visual acuity, glare, and ability to perform usual activities.
- Monitor pain level postoperatively. Sudden onset may be caused by a ruptured vessel or suture and may lead to hemorrhage. Severe pain accompanied by nausea and vomiting may be caused by increased IOP.
- Assess gradual adaptation to lens implant, contact lens, or glasses.
- Keep the patient comfortable and advise him not to touch his eyes.
- If eye patch or shield is in place, advise using it for several days as prescribed, to rest and protect eye, especially at night.
- Caution the patient against coughing or sneezing, any rapid moment, bending from the waist to prevent increased IOP for first 24 hour. Instruct the patient to avoid heavy lifting or straining for up to 6 weeks, as directed by surgeon.
- Advise patient to increase activity gradually; can usually resume normal activity the day after the procedure.
- Teach proper installation of the eye.
- Encourage to follow up ophthalmologic examinations for corrective lenses and checking of IOP. Adjustment to eye glasses to correct vision may take weeks.
- Advise the patient not to get soap in the eyes.
- Advise the patient to avoid tilting the head forward when washing hair, and to avoid vigorous hand shaking, to prevent disruption of the lens until cleared by the surgeon.